The present invention generally relates to a selective catalytic reduction (SCR) device for converting NOx in the gas stream into H2O and N2. More particularly, the present invention is directed to a catalyst loading device for loading and unloading catalyst blocks in an SCR, and methods therefor.
SCRs using catalyst blocks are often used in applications where NOx removal from flue gases is needed. In such cases, the SCR catalyst blocks are placed within the SCR reactor through which the combustion flue gases are conveyed. In order to remain effective, the catalyst should be protected from accumulation of particulate contaminants, which may deposit on the catalyst or otherwise restrict gas flow to and/or through the catalyst. Also catalyst is deactivated over time by the NOx removal process. In either case, removal and replacement or reloading of a catalyst may be periodically required.
Typically, catalyst loading devices used in the industry run on the lower flanges of the overhead catalyst structural support frame or dedicated overhead trolley beams. This means that the shapes of the catalyst supporting beams are typically constructed of overhead trolley beams with flanges. These flanges continue to be a problem since they can collect ash which can fall off and are a starting place for catalyst pluggage.
Catalyst loading device structural support frames that require lifting from underneath the catalyst blocks continue to be a problem since they must be wider than the catalyst blocks, requiring extra space on one side of the block for the structural support frame, which also increases the overall width of the catalyst reactor box.
One method of loading and unloading catalyst blocks in a SCR device typically uses pry bars for final placement, which may increase the chance of personal injury.
It would be desirable to provide a catalyst loading device that eliminates the need for overhead trolley beams with ledges in the form of the support beam flanges to prevent ash build up collecting on the SCR reactor box and provides an advantageous lifting mechanism suitable for integration into the SCR unit, which remains of significant commercial interest in the industry.